docs: def get_metadata(self, filename):
          '''Fetch all available metadata'''
          dest = self.path(filename)
          with open(dest, 'rb', buffering=0) as f:
              checksum = 'sha1:{0}'.format(sha1(f))
          return {
              'checksum': checksum,
              'size': os.path.getsize(dest),
              'mime': files.mime(filename),
              'modified': datetime.fromtimestamp(os.path.getmtime(dest)),
          }